need some help with buff n' blend + muff fuzz pedal

[foxfire]

as it says i just wired these 2 pedals together. this is what i used to build the blender, http://www.geocities.com/jrtookmyfalseteeth/buffwire.gif. and i built the muff fuzz from the layout over at ggg. now as far as i can tell the blender is working. the problems i'm having are,
1) when i turn the blend pot and or the muff's pot i get a static white noise like they are bad pots. i don't have them in an enclosure yet but since i only get the noise when i'm actually turning the pots i don't think that is the issue.
2) the muff is hardly in the mix even with the blend pot maxed on the fuzz side. now i do have them sharing a single 9v because i ran out of battery clips so i don't know if that is part of the problem?
just to note the muff fuzz worked fine before i wired it in to the blender. also to note i used a MPF102 in the blender and i used two 1m resistors in place of the two 4.7m resistors. other than that everything is stock.

[foxfire]

for now i'm saying never mind. i think i know what i did wrong.

[foxfire]

well in rushing to get it wired up before dinner i crossed the ground and input wires to the blender. swapped the and now it works, but i'm getting a bad hum and hiss. it isn't in an enclosure like i said and i don't think any of the second story outlets in my house have a proper ground so i'm not too worried about it yet. i'll have to check it in the morning when i don't have to worry about people sleeping.

[foxfire]

well i'm still getting as hissing noise like some really pissed off crickets with the muff fuzz turned up. with the blend pot set on clean signal the hiss is gone. so is the muff fuzz not a good candidate for this type of blender?

[foxfire]

i assumed that the muff fuzz was too loud for this blender so i swapped a cap in the fuzz to drop the signal a bit and added Mark Hammer's SWTC to the fuzz. now the squeal is mostly gone. i'll need to play with it a bit more to get it 100%.

[WXB200]

I cant get the Buff 'N Blend to work at all...

[foxfire]

huh, i did end up getting the pedal to sound good and used the buff n' blend on another pedal so i know it works. without more to go on i would suggest looking at your wiring and double check that your transistor is in correctly?

[okuzster]

sorry for bumping, i am pretty new. i tried to do buff n blend but couldnt make it and have no idea why is it not working.

first i build it on breadboard, it didnt worked and i thought there should be a disconnected wire somewhere cause i worked messy. then i made a pcb but same result. then i rebuild it on breadboard, i tried reversing capacitor, transistor that maybe i put them in wrong direction, nothing.

it passes dry channel when battery not wired, after wiring battery, there is no sound.

thanks in advance, i would be very greatful if i can fix this.

edit: scheme is this

[Kipper4]

post up a link to the schematic please
and your transistor leg voltages.

[okuzster]

i edited the earlier post with added schematic. transistor is 40v, looks exactly like this:

[Kipper4]

Just for clarity that my friend is a layout NOT a schematic


The schematic is half way down this pdf

http://www.guitarpcb.com/PDF%20Files/Buff%20N%20Blend.pdf

I meant use your multi meter to tell us the voltages on the transistor legs on the pcb/breadboard.

Drain=  volts
Gate=   volts
Source=  volts

[duck_arse]

everything kipper said, plus welcome to the forum, and can you post up some photos of the thing that you built, or the thing on your breadboard, please?

[okuzster]

sorry, i am still learning.

so i am trying but all i can is;

gate to source or source to gate i am getting values around 580 ohm, i couldnt read any value from drain. (i checked google and all i can found are about ohms, couldnt find volt)

about schematic, i draw it myself from layout, here is what i draw (not sure if clear, i draw it for myself) and empty pcb



and the breadboard



and thanks for the welcome

[bloxstompboxes]

well i'm still getting as hissing noise like some really pissed off crickets with the muff fuzz turned up. with the blend pot set on clean signal the hiss is gone. so is the muff fuzz not a good candidate for this type of blender?

Some really pissed of crickets, is the new name of my band. I am claiming it and it is now copyrighted. Thank you all. lol.

[Kipper4]

Sorry yet agian I forgot to welcome.

to use the multimeter to test the transistor voltages
apply the black probe to your ground.
poke the red probe on each leg of the transistor seperatly. try not to short them.

Dont set the meter to Ohms set it to Volts dc.

read the meter when set to volts dc
on the meter the DC volts looks like this.
____
----   V

each leg of the transistor (in this case a FET field effect transistor) is assigned a name
Drain
Source00
Gate

Check which transistor you used and google the data sheet for it.
on the sheet will be a diagram telling you which pin is which
write down the powered up transistors voltages and report back please.


Check this out where the guy is checking the power supply of a motor

http://en-us.fluke.com/training/training-library/test-tools/digital-multimeters/how-to-measure-dc-voltage-with-a-digital-multimeter.html


Rich

[okuzster]

thanks, that's make sense.

i left them all at workshop, so cant check now, i'll write when i check the volts.

one thing only, is the volt value should change when there is signal sent from guitar? (i mean when i hit the strings) even if so or not, i'll test it with muted strings. let me know please if there is anything i should care about.

[Kipper4]

In stomp boxes there are two voltages granted.
The dc voltages used to power the componants and make them work and carry the AC through the circuit
And the ac voltages, your guitar signal.

We need to know the Dc volts to see if you componants are working right.
I don't think I've ever used a meter to measure AC volts, so plugging in the guitar shouldn't make any difference to dc.
I hope your understanding is growing.
To help you on your way here's an article on schematic reading.
All this stuff can take a long time to learn but it's worth it.
You could carry on making stompers in a dot to dot style without understanding but something tells me if you have a breadboard that's not the case.
If I'm way off or I should shut up.
Just say.
Rich

[Kipper4]

I and many more of us have been where you are.
We're here to help.
The buff and blend is a nice little circuit but be advised it may not work well with all effects.
But we won't know for sure until you get it working.

Christmas 2012 I started here, I've been here nearly everyday since, be it banter, stupid questions, helping others whatever else.
I am eternally grateful for the best diy forum on the web.
Stompers I salute you and bow to your superior knowledge and kindness.
Rich

[okuzster]

thanks a lot, my understanding definitely is growing. you said there is an article but i cant see it.

i gonna try this buff and blend with my big muff pi clone behringer vd1, after that i wanna build my own big muff pi clone (changing values on breadboard and finding best ones for my own taste), but will see. things going harder than i thought.

i am really glad now being part of this community. wasnt expecting much while writing but i can see now it would be a big loss not writing.

[Kipper4]

Let's look at a bit of the circuit

In this post I'm using the schematic from Guitarpcb

Link to the doc
http://www.guitarpcb.com/PDF%20Files/Buff%20N%20Blend.pdf

R1 is a large resistor to discharge the charge held by the capacitor c1 when the effect is switched to bypass, so as the true bypass switch does not pop when you turn the effect back on

C1 the input capacitor (cap for short) somewhat shapes which freqauncies go through from the guitar to the circuit.

R2 R3 are two equal value resistors. One hooked up to the positive rail +9v the other is hooked up to ground (gnd) this is called a voltage divider.
Ohms law (google it) the single most important piece of math theory a stomper will use.
Ohms law tells us that the node (place where the two resistors meet in the middle)
Will be half of our supply voltage.
When using +9v
This shows us that the gate of the fet which is connected to the same node will sit at 4v5 (another way of saying 4.5V)
So now we know that the transistors gate should sits at 4v5
Now look at the drain Q1 it is directly hooked to the positive rail +9v
So we know what two of the voltages on the fets legs are.


Can you see anymore voltage dividers?

For info capacitors block the passage of DC volts. But let AC volts through.

Please note this is not an exhaustive explanation of what everything does. It is just aimed at getting the reader interested enough to want to know more.
An exhaustive explanation would be beyond my pay grade.

I hope this helps someone, if anyone else wants to chip in feel free and if I'm wrong about anything
Chip in too.

Rich